Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

Buy Site Supporter Role (remove some ads) | LPF Donations

Links below open in new window

FrozenGate by Avery

12x Murder Fund! + Graph!

Re: 12x Murder Fund! (Complete!)

@ IgorT:

The sensor that you have used, is just a photodiode or phototransistor that you have used as switch for the counter, or is a photodiode that can be used as level output measurer ? ..... or, in alternative, can you place a simple piece of glass in the beam at 45 degrees, for take out a fraction of the beam ?


Just an idea ..... if you need, i can draw a circuit, for that, and if for any luck you have a photocell, instead a photodiode (or a piece of cell like the ones in solar panels and solar powered calculators), is also better , cause it's a photo-battery, so it need also less or almost no circuitry ;)

It's just a photo-diode that detects IF there is light above a certain minimum cut-off level. The replottings are meant to test what happens in between.

Problem is, i made an assumption that if a diode will die, it will die PROPERLY, as in LED, or at worst like a "BDR-S03", which still lases a few mW (which would get ignored by the sensor).




As for the circuits, unless you also have time to MAKE them, don't bother, cos i don't have the time. :(



As i said, the replottings were supposed to do these checkups, but the >150h the first 8x survived lulled us all into a false sense of safety, causing me not to check every single hour.



P.S. Checking degradation on the fly would also require a constant temperature setup for each diode... They warm up quite a bit during cycling.. Not enough to call them hot, but enough to reduce the power a little, altho a simple instrument might not even notice this..
 
Last edited:





Re: 12x Murder Fund! (Complete!)

As for the circuits, unless you also have time to MAKE them, don't bother, cos i don't have the time. :(

If you are not in hurry, for me is not a problem to make it, only i need few days, cause actually i'm in and out from hospital too (not for me, my father fall in motorcycle and it's actually recovered, so i'm carrying my mother in and out from hospital and all the rest, and this will be for others 2 or 3 days, probably ..... as if i had not enough problems already with home and work, also this :p)

Just let me know what you prefer ..... the circuit, the assembly with the photodiode, or sometting complete ? ..... i still have some lcd voltmeters around, so can assemble also the complete unit ..... and if you're using the photodiode as switch just for count the cycles and detect the fault, i personally suggest you to use the splitter method, so the unit used for keep an eye on the power, don't interfer with the working of your circuit (only you need a way for fit the sensor in the beam, maybe also just with an "helping hand", or a staff or something similar)
 
Re: 12x Murder Fund! (Complete!)

If you are not in hurry, for me is not a problem to make it, only i need few days, cause actually i'm in and out from hospital too (not for me, my father fall in motorcycle and it's actually recovered, so i'm carrying my mother in and out from hospital and all the rest, and this will be for others 2 or 3 days, probably ..... as if i had not enough problems already with home and work, also this :p)

Just let me know what you prefer ..... the circuit, the assembly with the photodiode, or sometting complete ? ..... i still have some lcd voltmeters around, so can assemble also the complete unit ..... and if you're using the photodiode as switch just for count the cycles and detect the fault, i personally suggest you to use the splitter method, so the unit used for keep an eye on the power, don't interfer with the working of your circuit (only you need a way for fit the sensor in the beam, maybe also just with an "helping hand", or a staff or something similar)


I have tiny solar panels and panel meters. If you can make the circuit, i can hook it up to the Torture Chamber...

Actually i think i currently only have one suitable panel meter, but only the 12x needs monitoring of this type. The 8x is just fine with standard replotting.



As for time. Sorry to hear about your trouble first of all, but there is no rush.

I'm sending money to Scopeguy tonight, to order a couple 12x's, even with USPS Express to me the voyage will probably take two weeks as he has to order and receive them first.


In the meanwhile i will keep torturing the poor 8x's i guess...
 
Last edited:
Re: 12x Murder Fund! (Complete!)

Ok, most of the things required to arrange a new test are in place.

But since there are many donation suggestions i want to explain something, just to make sure we're on the same page.


I would like to test this diode like in the good old days, when i was looking for a safe power, not confirming an unsafe one...


I want to test if 12x's are capable of delivering 500mW+ safelly. I want to proove they are better than 8x's.
If the second 12x lasts for 100h+, it will proove not only that the selected power was safe, but also that there is some room left to go higher.


We've already seen, that 390-420mA can be too much for SOME 12x's. Perhaps this low efficiency one was also one of the weakest diodes, as i usually expect to tell from their efficiency.
That does not mean that others will not survive this current, or even live a long and happy life there. We may see some or even many 12x's at 400mA living long and happy lives.

But i believe that retesting at a similarly high current would be too risky, that's why i would like to set the second one just over 500mW and see how long it lasts.



Because i want to do it this way, i did not want to ask for donations, because that leads to too many different and sometimes potentially dangerous requests and not to forget confusion about what to do for me.


If anyone from the potential donors wants to see me torture the 12x this way, you are more than welcome to contribute. If you don't, you'll still see me do it here, because i want to see it...

From my point of view, even tho i'm not rich, i can afford to part with one laser to see the newest laser diode around die (slowly) and learn from it... Especially since at this moment, PP money still seems more like hobby-money than real money to me, because of where i live (but i'm working on fixing that, i kinda suspect i'll have more respect for it then :angel:)...
 
Last edited:
Re: 12x Murder Fund! (Complete!)

sounds good Igor, I'm still willing to put some money in for you to test the diode your way, so you wont have to cover all the cost...:)
 
Re: 12x Murder Fund! (Complete!)

It will definitelly be tested at higher currents than the 8x's, we do want more power from it obviously, like i said, one thing is to proove the diode is better than 8x's.


Why would i even worry about this, when we read that 12x's require 300mW?

There was this question about reaching higher speeds with vibration reduction in the drive instead of higher powers, and the 12x's have this strangelly high Vf, reaching or even exceeding 6V in some cases. On average noticably higher than the Vf of 8x's.


What if the 12x is like the SF-AW of 8x's? Same power rating but a different manufacturer?

If another manufacturer made a diode rated for the same power but with a rounder beam, it would be possible to reach a higher power due to the lack of the beam profile corrector and possible other improovements.

If Pioneer used a diode from another manufacturer due to a better aspect ratio, only of the same power rating, it would be possible it would behave differently than the 8x's we are used to.


Some diodes would then exhibit same performance, others could be drastically different or even weaker than 8x's.



This is a very unlikelly scenario, but i really wanna make sure that they are reliable at 0.5W+, before recommending this power to anyone, as i would recommend an 8x for 400mW.

This is why it's important to me.
 
Re: 12x Murder Fund! (Complete!)

I'll pitch in for that type of testing too Igor...

Just waiting for someone to say where to send the money!
 
Re: 12x Murder Fund! (Complete!)

Count me in too. Should we just contribute it and add it to Flaminpyro's GB as the 'New Murder Fund'?
 
Re: 12x Murder Fund! (Complete!)

It will definitelly be tested at higher currents than the 8x's, we do want more power from it obviously, like i said, one thing is to proove the diode is better than 8x's.

Why would i even worry about this, when we read that 12x's require 300mW?

There was this question about reaching higher speeds with vibration reduction in the drive instead of higher powers, and the 12x's have this strangelly high Vf, reaching or even exceeding 6V in some cases. On average noticably higher than the Vf of 8x's.

What if the 12x is like the SF-AW of 8x's? Same power rating but a different manufacturer?

If another manufacturer made a diode rated for the same power but with a rounder beam, it would be possible to reach a higher power due to the lack of the beam profile corrector and possible other improovements.

If Pioneer used a diode from another manufacturer due to a better aspect ratio, only of the same power rating, it would be possible it would behave differently than the 8x's we are used to.
Some diodes would then exhibit same performance, others could be drastically different or even weaker than 8x's.

This is a very unlikelly scenario, but i really wanna make sure that they are reliable at 0.5W+, before recommending this power to anyone, as i would recommend an 8x for 400mW.

This is why it's important to me.

Uhm, costructively, is possible that these diodes are just "picked" 8x (mean, selected lots of production) ..... or also, there's a different possibility, just that the 8X (that someone pushed at 550 or 600 mW) are just made with a chip geometry that, dissipating better the heat, made them more resistent to the stresses, proportionally, that the "new" 12X ones ..... or also, maybe a different coating of the reflective faces in the cavity increased the efficency, but at the same time, that different coating is more easy to damage if overloaded ..... i mean, as example, that an 8X can be a 150mW CW diode that can resist to 400% overstress, where instead the 12X can be an effective 200mW CW diode, that instead resist only to 200% overstress .....

Thinking about that, i was wondering ..... for have a similar conduct, is enough, just as hypothesis, that the LD chip is more thin in the 8X and more thick in the 12X (i'm NOT saying that the things are so, i'm only making hypothesis, ok ?) ..... just as hypothesis, if a thin chip can dissipate more heat than a thick one, can be more resistent to overstresses than a thicker one, also if the thicker one is built for generate more power in normal conditions .....

Ofcourse, the reasons can be also differents, just, wondering if someone of the users that have 8X and 12X, can take some macro of the chips through the windows, just as curiosity .....
 
Re: 12x Murder Fund! (Complete!)

I'm also in on a donation for this safer ~500mW test. First let's see how reliable it is!
 
Re: 12x Murder Fund! (Complete!)

Just thinking that it may be easier to just send the money to Igor, and then let him order a 12X drive wouldn't it?
 
Re: 12x Murder Fund! (Complete!)

I may have missed it, but is there a central location (like the first post) where data is being posted about these babies? To start with I'm talking basic things like P-I-V plots.
 
Re: 12x Murder Fund! (Complete!)

Count me in too. Should we just contribute it and add it to Flaminpyro's GB as the 'New Murder Fund'?
This idea has merits, as Flaminpyro is going to order the burners for Igor & daguin which are listed under my name, (scopeguy20). -Glenn
 
Re: 12x Murder Fund! (Complete!)

Just thinking that it may be easier to just send the money to Igor, and then let him order a 12X drive wouldn't it?


Shipping $$$ would be insane and he would have to get taxed too I believ. If you pulled the diode, you can say its a $2 photo diode in the customs declaration..
 
Re: 12x Murder Fund! (Complete!)

In the Flaminpyro 12X GB, Sleds w/b sent to those, (like Dave) who want the sled, Igor always just gets diodes. :whistle: -Glenn
 





Back
Top